The main reason a Sony Playstation 2's laser goes bad is that the little white gear that moves the lens gets out of place. Sometimes the laser lenses just wear out. Now, you can switch your PS2 to diagnostic mode to fix this issue for the time being. What fixed my laser is that I clicked a little black switch in the back of the lens itself. I also washed the lens with rubbing alcohol. Now my laser works like a charm, with barely any issues (Knock on wood). Although a metal piece fell out of mine and I have no clue where it goes in the end O.O.